1. Field of the Invention
The present invention relates generally to the management of the distribution of applications and databases between electronic devices and more specifically, to a novel management system for selectively distributing applications and databases from a computer to a plurality of intermittently connected handheld devices.
2. Description of Prior Art
With the rapid advancement of semiconductor, storage, and display technologies, handheld or mobile devices have become increasingly popular. The handheld devices, such as a Palm Pilot, a Windows CE, a Zaurus, a Psion, a smart phone, or an intelligent pager have become very versatile. A handheld device may be used as a Personal Digital Assistant (PDA) providing such functions as e-mail, address book, calendar. Internet freeware, such as games, may be downloaded to the handheld device for leisure use. Business related applications and databases may be installed to improve productivity.
In an organizational setting, such as a corporation, an important issue in managing handheld devices is the distribution control of the applications to be installed in the handheld devices. For example, a corporation may develop several different sets of automated work procedures for handheld devices: customer account management procedures for the sales department; machine operation procedures for factories; and inventory control procedures for warehouses.
It may be valuable that the sales department devices receive only the account management application, the factory devices receive only the machine operation applications, and the warehouse devices receive only the inventory control applications. It may also be useful that, based on employee roles, devices belonging to different employees receive different sets of applications, matched to the employees"" respective roles. A manager""s device, for example, may get an employee evaluation tool which is not distributed to an employee""s device. Furthermore, an organization may provide an additional set of applications, such as utility software, games, and other information databases. At the user""s discretion, a subset of these applications may be chosen for download to each handheld device.
Handheld devices install applications through the synchronization process which is typically performed between the device and a PC. First, the application must be accessible by the PC which, through its serial port, is connected to the target handheld device. The PC software may be executed to load the target application into an xe2x80x9cinstallxe2x80x9d directory accessible by the synchronization manager software. The synchronization process is initiated by pushing a handheld device button, such as the HotSync button in Palm Pilot. Immediately after the button is pushed, synchronization manager software, such as the HotSync Manager used with Palm Pilot""s, in the PC takes over the synchronization process during which the applications loaded in the xe2x80x9cinstallxe2x80x9d directory are downloaded and installed into the handheld device.
This software distribution process is a standalone system synchronizing software between a PC and a handheld device, it does not have centralized software distribution management functions. To distribute an application among many handheld devices, the application must first be copied to the PCS of all the target handheld device owners. After that, it is up to each owner to conduct the synchronization process to install this application from the PC in to the handheld device. Hence, there is no efficient way to determine which handheld devices have the target application installed.
An alternative way of distributing handheld applications within an organization, is to have a centralized server that manages a user pool, a handheld device pool, and an application pool. To install an application, a handheld device must first connect to the network and make such a request directly to the centralized server. It is the server""s responsibility to authenticate the handheld device and its user, to authorize the application installation request based on the user profile, the device usage, and a pre-configured access-control policy. If the application installation request is authorized, the server downloads the target applications to the device.
The centralized server may update the application status of the handheld device, e.g., what applications have been installed in this device?, update the handheld device status associated with the target application that are managed by the centralized server, e.g., what devices have downloaded this application?, and log this download activity in the server""s event logs. The event logs and the application status recorded by the server may provide important information in managing software distribution.
The traditional client-server model assumes a persistent network connection which exists for both the clients and the server. Therefore, the client requests and the corresponding services performed by the server are more interactive. Every time a client decides to examine the applications managed by the server that are available, the client may connect to the server, retrieve an updated list of available applications, choose the desired applications while the client is still connected to the server, and proceed to download the selected applications from the server. The client has no need to keep the list of applications and the status of these applications. The list of applications available to the client may be retrieved, and the status of each application on the client device determined during the interactive real-time query exchange between the client and the server.
The drawback of the traditional client-server model, however, is that the network connection of the handheld devices is not persistent. Only occasionally do handheld devices connect to the network, and typically the connection, through a low-bandwidth medium such as a modem or a serial cable, lasts a short time. It may be advantageous for each handheld client to maintain a list of applications that are available from the server.
Maintaining a list of applications may be accomplished in the following ways. The user of a handheld device may run software to perform application selection based on the application list while the device is not connected to the network. Therefore, no time-costly interactive application selection process occurs when the client is connected to the server.
Alternatively, while the device is disconnected, it may investigate and record the status of each application in the application list. This way, when the client is connected to the server, all information about the application status is already available. The server does not have to interactively query client for the status of each application, thereby further improves the efficiency of bandwidth and time usage when the client remains connected.
Many handheld devices have built-in support of a synchronization function which compares the two records with the same ID respectively from the device and a synchronization host and, based on an application dependent set of rules, determines if a record from one side override that of the other side or if other actions, such as replicate both records to the other side with a new ID should be taken.
The retrieval of the application list from the client by the server may directly use the synchronization function provided by these handheld devices.
In accordance with the aforementioned needs, the present invention is directed to a method and apparatus of a server-based handheld application management system. In this system, the server manages a pool of users, a pool of handheld devices, a pool of handheld applications, and a set of access-control policies governing which handheld devices owned by what users are authorized to download a subset of the applications.
In the present invention, the clients are handheld devices that are only occasionally connected to the server for distribution of applications. When they are connected, typically the connection lasts a short period of time and is through a low-bandwidth medium such as a modem or a serial line. The process of a client requesting for application download and the server servicing this request must be performed while the requesting clients remain connected to the network.
According to the present invention, an application list structure is provided to record the status of all applications available to a client, that are managed by the server. The status for an application may indicate if this application is installed in a client and if it is selected to be installed to this client next time this client connects to the server.
When a client connects to the server, a method is provided for the server to retrieve the application list from this client and to download a subset of applications in the list to the client, based on the status of each application in the list as well as the up-to-date access-control policy, and to update the application list in the client based on the up-to-date access-control policy.
Accordingly, the client updates its application list by allowing the user to select the applications to be downloaded the next time this client synchronizes with the server and by allowing the user to delete the applications that are installed in this client. This activity may be performed at any time, regardless whether the client is or is not connected to the network.